Hornresp

That seems to be characteristical for conical horns. I remember Tom Danley posting about this, but not where, maybe the audio asylum. In the unity and synergy horns this is countered with a short horn segment at the end of the horn which has a slightly wider angle than most of the horn. But it seems that hornresp cant simulate the radiation pattern for multi segment horns, so i cannot check if this is true.
 
Paul W said:
Hi David,
First, thanks for a great tool!

Question...
With a conical or OS, I am seeing directivity dramatically narrow just above LF cutoff. Is this because there is no baffle or mouth treatment? If not, what does cause it?
Thanks,
Paul

Hi Paul,

It gets a bit complicated, but essentially the effect is due to the shape and size of the wavefronts in a conical horn relative to wavelength. Note that the directivity narrowing actually occurs in practice - it is not just in the simulation results that you will see it.

Kind regards,

David
 
Hornresp Version 19.00

Hi Everyone,

Hornresp Version 19.00 has just been released. Changes are:

1. Offset driver horns can be modelled. See Note 7 on page 15 of the Help file for details.

2. The tapped horn option is selected differently. See Note 8 on page 15 of the Help file for details.

3. The Multiple Drivers tool is now the Driver Arrangement tool. The number and position of drivers can be specified.

4. The profile information for the left and right side walls of a rectangular cross-section horn is now also exported, where the data can be directly calculated. See Note 14 on page 17 of the Help file for details.

5. A bug in the Tapped Horn Wizard which “froze” the program under some circumstances, has been fixed.

Kind regards,

David
 
Paul W said:


David,
Would you say a bit more about this? I'd like to understand the root cause a little better.
Thanks,
Paul

Hi Paul,

The following references may be of some help - they cover in reasonable detail the key factors that influence the directional properties of horns.

* 'Acoustical Engineering' by Harry F Olson
* 'Acoustics' by Leo L Beranek

Kind regards,

David
 
revintage said:
Hi David,
How do I simulate a horn with a compression driver, in my case JBL 2441?

Hi Lars,

Just the same as for any other driver :). One problem could be finding the driver parameter values, as they are not normally released by the manufacturer. It will also be necessary to determine the throat chamber size, which is in the compression driver itself.

Contrary to popular belief, Hornresp models the power response of compression-driven midrange horns quite accurately, provided that the input parameter values are correct.

Kind regards,

David
 
Error in Version 19.00

Hi David,

I had a problem in Version 19.00-08041: after adding a speaker the program created an additional entry "002" that gave a "Subscript out of range" error everytime I tried to open it, and when clicking OK in the error window Hornresp shut down.

I could not remove this entry in version 19, but was able to get rid of it by going back to version 18.30 which opened the empty entry, and allowed me to delete it. After reinstalling version 19.00 all seems fine.

Just thought you should know, thanks for Version 19.
Regards,
 

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Re: Error in Version 19.00

tb46 said:
Hi David,

I had a problem in Version 19.00-080414: after adding a speaker the program created an additional entry "002" that gave a "Subscript out of range" error everytime I tried to open it, and when clicking OK in the error window Hornresp shut down.

I could not remove this entry in version 19, but was able to get rid of it by going back to version 18.30 which opened the empty entry, and allowed me to delete it. After reinstalling version 19.00 all seems fine.

Just thought you should know, thanks for Version 19.
Regards,

Hi Oliver,

Many thanks for the feedback. I suspect that you may have had two copies of Hornresp running at the same time, at some stage :). Editing, adding or deleting records using one copy of Hornresp while another one is also open, will generate the problem you have experienced. Could you please let me know if you had two copies of Hornresp running, sharing a common data file.

In any event, it is strongly recommended that only one copy of Hornresp be run at a time, and as mentioned in a previous post, under no circumstances should an earlier version of the program be used after the data file has been opened by a more recent version.

Incidentally I have just released a minor upgrade which fixes two subtle user interface bugs that I found yesterday. Product Number 1900-080418 refers.

Thanks again for the excellent feedback.

Kind regards,

David
 
Re: Error in Version 19.00

Hi David,

You are correct, I have had two copies of Hornresp running at the same time before. It is interesting, that I have not experienced any problems like this earlier. I quite frequently have had one window open to see e.g.: the input parameters or the SPL curve while working in another. Well, got to stop doing that, it's easy enough to work around.

I have been amazed how forgiving your software is in comparison to many others out there. Thanks for the steady stream of updates.

Regards,
 
Re: Re: Error in Version 19.00

tb46 said:
Hi David,

You are correct, I have had two copies of Hornresp running at the same time before.

Hi Oliver,

Many thanks for the confirmation. I have now included a cautionary note in the Readme.txt file supplied as part of the download package, warning users not to edit, add or delete records while running multiple copies of Hornresp.

Please note that it is quite okay to run multiple copies, provided that they all have the same version number. The important thing is not to edit, add or delete any records while the multiple copies are running.

Thanks again for the very useful feedback.

Kind regards,

David